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Are you having trouble with fungus gnats? Most tropical plants will thrive in humid conditions. Increasing humidity for your plants is great but can cause the soil to retain a lot of moisture and over time it can lead to fungus growing in the soil. Fungus is not always harmful to your plants but it does attract those pesky fungus gnats.
When I made my own greenhouse cabinet for my houseplants, to help give them a humid tropic-like environment, I did not even think about the possibility of Fungus Gnats. It did not take long for my greenhouse to fill up with gnats.
For more tips on increasing humidity for your houseplants check out: 9 Ways to Increase Humidity for Your Houseplants
Fungus gnats do not usually do much harm to your plants. If gone untreated for a long time they can run out of food and start to go after your plants. But this will take a really long time. I bet you will be fed up with these flying pests before it gets that far. Don’t worry though! I’m about to let you in on how I got rid of fungus gnats for good.
If you have not encountered a fungus gnat infestation yet, trust me, you don’t want to wait for it to happen.
FUNGUS GNAT PREVENTION
1) Stop Over Watering!
Not only will extra moisture be a breeding ground for fungus and then fungus gnats, it will also kill your plants. Do a soil finger test before water or use a moisture meter. Only water if the plant really needs it!
2) Cinnamon in Soil to Prevent Fungus Gnats
Cinnamon is a the real MVP! There are a lot of great uses for cinnamon when it comes to plant care. For one it is a great anti-fungal. It will help kill fungal spores before they can attack your plants or lead to a fungus gnat outbreak.
I like to make my own soil mix and I always add some cinnamon in it to help prevent mold and fungus from growing in the soil. If there isn’t any fungus to attract fungus gnats it will help prevent them from in the first place.
If your plant is already potted and it isn’t a good time to re-pot, you can always sprinkle a thin layer of cinnamon on the top layer of the soil. It will seep in the next time you water your plant.
You may also like : How To Make Your Own Soil & Why You Should
3)Remove any dead or dropped leaves
Fungus feeds on dead organic matter. It’s good to remove and dead leaves or stems before they decompose into the soil.Dead leaves are a feast for potential fungus.
4) Increase Airflow
You always want to make sure you are using an aerated, well draining soil mixture to prevent the soil from compacting and retaining too much moisture.
Also, if you do increase humidity for your houseplants or keep them in a grow tent, propagation box or greenhouse, make sure they are getting enough air circulation. Whether that means adding in a fan or just opening the lid/door once in awhile so you plants can get some fresh air.
5) Semi Hydro to Keep Fungus Gnats Away
Converting plants to semi hydroponics can greatly reduce the risk of fungus gnats. It is a lot easier to see what is going on with your plants when using this LECA(Lightweight expanded clay aggregate,)a soil-less growing method. It will be easier to keep an eye on the roots of your plants, remove any dead/rotting matter and flush your plants. Fungus gnats are also a lot less likely to lay eggs in a soil-less medium like LECA (Lightweight expanded clay aggregate,) which is used in Semi hydroponics.
If you are interested in trying out Semi Hydro you can check out this: Semi Hydro Step by Step Guide
6) Mosquito dunks or bits
You can add mosquito bits or dunks to soil as preventative or soak them in your watering can. I like to use mosquito dunks as they are easier for me to find in Canada. I personally will break one mosquito dunk in half and put it in my watering can. I then water my plants with the mosquito dunk water as I usually would water my plants. I just leave the dunk in my watering can and refill it as I need too.
TIP: Add some bits to your propagation boxes too
Controlling a Fungus Gnat Outbreak
1) Sticky Traps
Sticky Traps will effectively help trap fungus gnats. These sticky tabs are great for trapping different pests. However, they will not completely solve your fungus gnat problem as the gnats lay eggs in the soil.
4) Apple Cider Vinegar Mixture to Trap Fungus Gnats
If you already own Apple Cider Vinegar, you can make your own trap. Fill a little dish with some apple cider vinegar,a bit of water, a sprinkle of sugar and a couple drops of dish soap and this will help attract and catch fungus gnats. This is effective in catching the gnats already flying around. Like the sticky traps this will not get rid of the problem altogether.
3)Hydrogen Peroxide
Hydrogen peroxide is another household item I use for my plants. For fungus gnats you can mix 1 part water and 1 part hydrogen peroxide and use the mixture to water your plant. This will help kill the gnat larvae living in the soil. You will probably hear a bit of a sizzle when you pour the mix into the soil. That sizzle is the peroxide killing the gnat larvae and bacteria in the soil.
I only use this method as a last resort as the peroxide will kill both bad bacteria and good bacteria and you want the good bacteria and nutrients to keep your plants happy.
Tip: If you must use this method I would give it a couple weeks and add nutrients via fertilizer OR re-pot in fresh soil. Re-potting is not always ideal as it can stress out your plant and slow down growth. Also, some plants like to be root-bound.
You may also like: Plant Pot Tips
4) Mosquito Dunks
Yes again! Mosquito dunks are on the list again because not only will they be preventative they still work when an outbreak is in full swing. This is my all time favourite method for getting rid of fungus gnats if you already have a problem.
And Bonus they can also take out mosquitoes!
I keep a dunk in my watering can at all times and just refill as needed. I do not even crush up the dunk. Just leave it to seep in the water and use that water when you water your plants.
Don’t Forget to follow me on Instagram: @thepeculiarrose
And let me know if you try any of these tips and what did and didn’t work for you.
May you also successfully banish Fungus Gnats from your indoor jungle!
Links for all the products I personally use: